1. Field of the Invention
The apparatus of the present invention relates to a device that employs phytoremediaton technique (plant and root-associated microorganisms) to purify indoor air by passing air through the soil in the planter. It also provides plants with moderate conditions for growth.
2. General Background of the Invention
The fact that common house plants culture microorganisms on and around their roots that can decompose volatile organic compounds has been demonstrated by Wolverton, et al. (1984) "Foliage Plants for Removing Indoor Air Pollutants from Energy-efficient Homes", Economic Botany, 38(2), 224-228 and B. C. Wolverton and J. D. Wolverton (1993) "Plants and Soil Microorganisms: Removal of Formaldehyde, Xylene and Ammonia from the Indoor Environment", Journal of Mississippi Academy of Science, 41(2):99-105.
In order to utilize the air purification effect of soil in the planter, it is necessary (I) to properly fertilize and water plants with a minimum task for maintaining growth of the plants, (II) to prevent the growth of mold and mildew in the soil which are harmful to the plants, and (II) to pass indoor air through the soil at a moderate flow rate.
In order to satisfy the above requirements, a planter stand equipped with a sealed reservoir to supply water for the soil and an air pipe was proposed. One side of the air pipe with air intake is extended into the soil, and a fan and light bulb are attached to the outer side of the pipe. The sealed reservoir provides the soil with fresh water for a long period of time, and the air pipe passes indoor air though the soil for air purification. The light bulb not only supplies a light source for growing plants in, but also generates heat to destroy toxic airborne microbes flowing inside the air pipe.
The conventional planter described above would be practical (I) if the planter were not too large, (II) if one could find a plant which has sufficient removal efficiency for all of the pollutants in indoor air, and (III) if the plant were strong enough and never withered. However, since the planter is to be placed inside a house, it is preferable that it be compact and also pleasing to the eyes.
Further, it is likely that the plant would have a reduced function for purifying air due to aging and withering because of improper care. It is also likely that we might find a new plant which is more suitable for removing certain air pollutants. In these circumstances, we would want to replace the plant in the planter.
Since the device described above has an air pipe extended into the soil, it is difficult to plant a new plant into the planter; it also makes it difficult for the planting to spread its roots. Therefore, it is necessary to use a large planter. After planting, the roots will begin to spread around the air pipe therefore, it is possible to have root damage at the time of replanting and a lot of dirt will be scattered making a mess. If one makes an attempt to replace the whole planter, the air pipes also need to be replaced. Therefore, a lot of replacements of air pipes are needed. With this in mind it has been very difficult to replace the plants, and a lot of care must be taken in the maintenance of such a plant stand.
The present invention proposes a new plant stand that is small, compact and easy to exchange plants which has indoor air purifying function.